Abstract Background and Aims In recent years, obesity has reached epidemic proportions, and it's a great challenge to choose an adequate treatment for obese ESRD patients. The aim of the study was to analyze the outcome in patients with peritoneal dialysis with different degrees of nutrition expressed through body mass index at the beginning of treatment. Method The prospective clinical study included 53 incidental patients, who started peritoneal dialysis between June 2006 and August 2015. According to BMI on the beginning of treatment, patients were divided into three groups: normal weight: BMI of 18.5 - 24.9 kg/m2, n=17, overweight: BMI of 25 - 29.9 kg/m2, n=25, obese: BMI> 30.0 kg/m2. n=11. Mechanical and infective complications, technique survival and patients survival were analyzed over 48 - months period. Results In terms of mechanical complications, there was no difference between the groups- malposition of the catheter (p = 0.769), leakage of dialysate (p = 0.462), hernia (p = 0.381). Exit sitе infection were most prevalent in group 3 - 1 episode/22 patient months vs 1 episode/30 patient months in groups 1 and 2, but without statistical significance (p = 0.272). However, the lowest incidence of peritonitis was in the group 3 - 1 episode/40 patient months vs 1 episode/30 patient months in group 2, and 1 episode/33 patient months in group 1, but even here the difference did not reach statistical significance (p = 0.624). Cardiovascular events – myocardial infarction, stroke and peripheral vascular disease were rare in all groups, with no statistical significance between groups. The incidence of hospitalizations was highest in the obese group – 1 episode/22 patient months vs 1 episode/27 patient months in group 2, and 1 episode/25 patient months in group 1 (p = 0.735). Kaplan Meier's analysis showed the worst, but not significant, survival of the technique in a group of obese patients (group 1 vs. group 2; p = 0.536; group 1 vs. group 3 - p= 0.662; group 2 vs. group 3 - p = 0.357). Also, overall patient survival was not differed between the groups (group 1 vs group 2 - p = 0.387; group 1 vs group 3 - p= 0.885; group 2 vs group 3 - p = 0.375). According to Cox's analysis, only values of total cholesterol at the end of the follow-up period (p = 0.027) and diastolic blood pressure (p = 0.013) were significantly associated with overall survival obese patients. Conclusion In the present study the degree of nutrition at the beginning of treatment had no significant effect on the outcome of peritoneal dialysis treatment. Therefore, patients should not be discouraged for peritoneal dialysis on the basis of BMI.